1. Field of the Invention
This invention relates to computers that accept external plug-in modules to provide additional functionality such as more memory, additional disk space, a networking capability or a wireless communication capability. In particular, the present invention relates to a plug-in module having a connector adapted for connection to a wireless communication system and a connector adapted to mate with the plug-in module as well as conventional plug-in modules.
2. Description of the Related Art
Modern technological advancements have increased the number of features available to a portable computer. Features include facsimile (fax) modems, additional communication interfaces, extra random access memories (RAM), or flash memories, and additional hard disk drives. These additional features if all incorporated into the portable computer will substantially increase the weight and size of the portable computer reducing the portability of the computer. Besides, any one user is not likely to need all the available features or be willing to pay the increased costs associated with having all the additional features.
A standard interface has been developed that allows computer designers and manufacturers to build modules that can be plugged into the standard interface. An application-specific module called a Personal Computer Memory Card International Association (PCMCIA) card can be removed and substituted for other PCMCIA cards depending on the configuration and functionality desired by the user. Thus, users are able to customize their portable computers to their particular needs at any given instant.
FIG. 1 shows a computer system 10 having a PCMCIA slot 12 for receiving a PCMCIA card 14. The computer system 10 can be a portable computer. The portable Computer 10 has a hinged display which permits the display to fold closed against the keyboard. The keyboard has keys that are arranged and large enough to enable an average person to type and input data comfortably. With the display facing the front side, the left side of the portable computer 10 defines a PCMCIA slot 12 for receiving and interfacing with PCMCIA cards. The PCMCIA card outline and shape are specified so that designers and manufacturers can provide cards that can be interchangably inserted into the PCMCIA slot. A user can slide the PCMCIA card 14 into the PCMCIA slot 12 leading to a keyed 68 pin connect&. The keyed 68 pin connector ensures proper mating between the PCMCIA card 14 and the PCMCIA interface of the portable computer.
The PCMCIA specification also specifies hot insertion and removal of any PCMCIA card. In other words, the portable computer does not have to be powered down before the user can swap PCMCIA cards. When the user is finished with a PCMCIA card, the PCMCIA card is simply removed and replaced with another PCMCIA card without having to power down the computer. Hot insertion and removal of PCMCIA cards provide ease of use and considerable time and power savings by not having to power down the computer. Power is saved by not having to use the disk drive to reload the data back into the memory of the portable computer. Some of the functions that are available from PCMCIA cards include high speed fax or data modems, Ethernet interfaces, additional RAM, flash memories, additional hard disk drives, multimedia applications, and wireless operations.
The prior art includes three types of PCMCIA cards: a Type I card, a Type II card, and a Type III card. FIG. 2A shows a Type I PCMCIA card 25. The length of the Type I card 25 is approximately 85.6 mm, the width is approximately 54.0 mm, and the height is approximately 3.3 mm. The connector area 27 of Type I card 25 includes a dual row 68 pin in-line connector. The dual row 68 pin in-line connector is keyed to aid proper connection to a PCMCIA mating connector within a computer system 10 such as the portable computer shown in FIG. 1.
FIG. 2B shows a Type II card 30. Type II cards are essentially the same as Type I cards except that the Type II cards are allowed to have raised sections which increase the thickness of the Type II card over the Type I card. A raised section 32 is shown on the top side of Type II card 30. A similar raised section corresponding to raised section 32 is on the bottom side of the Type II card 30. In adopting Type II cards 30, the distance from the center line of the 68 pin connector to either the top side of the card or to the bottom side of the card of connector area 34 is limited to a maximum of 2.5 mm which includes the raised sections of the Type II card. The raised sections permit designers and manufacturers to incorporate more circuitry and devices into the PCMCIA cards.
The prior art also includes Type I and Type II Extended PCMCIA cards. The Type I Extended and Type II Extended cards are the same as the Type I and Type II cards except for an extended portion. The extended portion extends 10 mm past the standard card length of 85.6 mm before the height can be increased to a bubble area. The bubble area provides additional space for extra circuitry that is included in the Type I and Type II Extended PCMCIA cards. The lower substrate of the extended bubble area measured from the centerline of the 68 pin connector to the bottom of the card is the same thickness for the entire length. In other words, the Type I Extended card and Type II Extended card retain the 2.5 mm distance from the centerline of the 68 pin connector to the bottom side of the card. The extended bubble area measured from the centerline of the 68 pin connector to the top of the bubble is approximately 8.0 mm. The thicker bubble area of the Type I Extended card and Type II Extended card permits designers and manufacturers to incorporate the thicker conventional RJ-11 and RJ-45 standard connectors.
FIG. 2C shows a Type III card 36. Connector area 34 of Type III card 36 includes a dual row 68 pin in-line connector that is keyed to aid insertions. The Type III PCMCIA card is thicker so that additional devices can be accommodated. Type III cards are often found to include small form factor hard drives. Type III cards have the same outline as Type II cards except that the Type III cards are twice the thickness. However, the centerline of the 68 pin connector of the Type III card to the bottom of the card maintains the PCMCIA standard of approximately 2.5 mm. The centerline of the 68 pin connector of the Type III card to the top of the card is approximately 8.0 mm.
One of the newest technologies to utilize the PCMCIA interface of portable computers is wireless technology. A wireless PCMCIA link provides portable computer users with the ability to send and receive data and fax transmissions using cellular technology. A major problem associated with designing radio communication solutions for portable computers is coupling the intended data/signal to the wireless medium and retrieving that same data/signal from the wireless medium at the other end. Antennae are used to send and retrieve data from wireless mediums. Thus, in order for a portable computer to access a wireless medium, the portable computer has to have an interface capable of coupling to an antenna for transmitting and receiving wireless transmissions.
FIG. 3 shows an example of a wireless PCMCIA link utilizing cellular technology for fax/data transmissions. A portable computer 50 is coupled to a cellular phone 55 to obtain access to wireless service via a PCMCIA Type II card 58. A PCMCIA Type II card 58 provides an interface between the portable computer 50 and the cellular phone 55. The PCMCIA Type 11 card 58 is coupled to a connecting cable 52 which is coupled to a phone cradle 54. The phone cradle 54 provides a connection to the cellular phone 55. The cellular phone 55 provides the external antenna and the necessary circuitry to establish a wireless link to the cellular technology. The PCMCIA Type II card 58 includes circuitry to permit the portable computer 50 to exchange data with the cellular phone 55. However, the additional cabling 52 and connectors introduce associated problems that often lead to loose, misaligned, or open connections. The additional cabling 52 attached to the PCMCIA Type 11 card 58 is prone to being sheared or broken with use. Moreover, the external components, the connecting cable 52, the phone cradle 54 and the cellular phone 55 take away from the portability of the computer. The existing PCMCIA interface does not provide an internal antenna interface. Therefore, it is desirable to design an improved way to implement an interface that provides users of portable computers access to wireless technology which improves and overcomes the disadvantages of the prior art. The improved interface should be low cost, blind mateable, capable of repeated insertions, utilize the existing PCMCIA standard interface, and be capable of operating over a wide range of frequencies.